A typical communications device and a typical information communications technology (ICT) device include a power supply apparatus, a service board, a cooling fan, and the like. The power supply apparatus is responsible for receiving one or more power source inputs outside a device, and converting the power source, which is input from outside the device, into a power source available to a load (including the service board, the cooling fan, and the like) in the device.
As shown in FIG. 1, when N (number of) power sources are input to the power supply apparatus, N power source conversion modules need to be disposed in the power supply apparatus. Each power source conversion module is connected to one power source, that is, the N power sources need N power source conversion modules, and the power source conversion module converts an output voltage of the power source into a direct current voltage required by a load in a device, which generally is −48 volts (V) or 12 V. To meet high reliability, N+N standby is generally performed on power sources, that is, each power source has a standby power source. Each power source conversion module receives power from one power source. Correspondingly, N+N standby is also performed on the power source conversion modules, where N power source conversion modules receive power from N line-A power sources, and other N power source conversion modules receive power from N line-B power sources.
Therefore, when N+N standby is performed on N power sources, N+N standby also needs to be performed on the power source conversion modules. The power supply apparatus needs a large number of power source conversion modules; especially, for a high-power device, the power supply apparatus needs more power source conversion modules. For example, for a device with power consumption over 20 kilowatts (kW), the number of power source conversion modules may exceed 16. Therefore, the power supply apparatus needs a large number of power source conversion modules, which increases power supply costs of a system, and also increases space occupied by the power source conversion modules.